Pressure-operated tool

ABSTRACT

A pressure-operated tool particularly for the setting of fastening elements, such as blind rivets. The tool utilizes a pressure cylinder operation associated with one end of a pivotal lever whose other end operates the pressing or draw unit for axial motion of the latter.

v United States Patent 1 1 3,660,885 Elflein [4 1 May 9, 1972 [541 PRESSURE-OPERATED TOOL 2,053,720 9/1932 l-luck ..72/391 3,088,616 5/1963 Pickford.... ..72/391 [72] ??233323 874 Bad 3,491,578 1/1970 Brenann ..72/391 [22] Filed: 1970 Primary E.\'aminer-Andrew R. .lohasz [21 APPL No; 17,115 Assistant Examiner-Leon Gilden Attorney-Woodhams, Blanchard and Flynn [30] Foreign Application Priority Data I 57 ABSTRACT Apr. 21, 1969 Germany ..P 19 20191.3 1 I r A pressure-operated tool particularly for the setting of fasten- [52] us Cl I I I U 29/2 4153 B91 ing elements, such as blind rivets. The tool utilizes a pressure [51 1 Int Cl 1, 11/00 cylinder operation associated with one end of a pivotal lever whose other end operates the pressing or draw unit for axial [58] Fleld of Search ..29/2f13.53, 243.5, mofion ofthe latter.

[56] References Cited 9 Claims, 2 Drawing Figures UNITED STATES PATENTS Huck et a1. ..72/391 PRESSURE-OPERATED TOOL The invention relates to a pressure-operated tool, in particular for setting of fastening elements, for example blind rivets, with a pneumatic or hydraulic drive means and a setting unit, in particular a pressing and/or draw unit, translatably movable through said drive means in a bearing housing.

The drive of known tools of the mentioned type (DAS No. 1,217,175) is formed by a pneumatic and/or hydraulic cylinder-piston unit, the piston rod of which is guided with respect to the cylinder housing. Said cylinder housing is arranged concentrically to said piston rod and is provided with parts of a chucking mechanism by engaging a blind rivet draw mandrel. Since the pressure required herefor can be obtained only with a large piston surface in the drive, these known tools are difficult to handle, tire the operating personnel very quickly due to their considerable weight and are suitable only when expensive, complicated and unhandy additional devices are used for operations in angle comers or other difiicult to reach working places.

I In order to. avoid these disadvantages the basic purpose of the invention is to further develop a tool of the above-mentioned type with means of simple construction in such a manner that it is suitable, without requiring additional devices, for operations in places which are difficult to reach and furthermore is lighter and'more handy than prior tools. This is attained by causing the drive to engage the setting unit with a first lever arm-of a two-arm lever which is pivotably guided in a pressure tight manner through anopening in the wall of a cylinder chamber and projects to the outside thereof and further by causing the second lever arm to form together with the cylinder chamber a rotary or swiveling piston-cylinder unit.

Because of these simple structural measures, the cylinder housing of the drive means projects only on one side radially from the bearing housing of the setting part so that the latter can be easily guided to working places which are difiicult to reach, for example into angle comers and can be used for many different operations. Furthermore, the construction of the drive of the invention with a two-arm swiveling piston can, with the least structural load, assure a great force transmission by making the first lever arm considerably shorter than the second lever arm. By so doing, the swiveling piston can be constructed with only a small surface and is thereforeparticularly economical of space and yet provides a sufficient acting force to assure the capability of the tool for setting of blind rivets, punching of sheet metal, clamping of workpieces or piston being arranged inthe zone of the sector top. Such a cylinder chamber can be manufactured at a small expense in large numbers including the bearing elements for the swiveling piston and can be gripped easily by hand so that it can be arranged as handle on the bearing housing of the setting means in the preferred embodiment of the tool.

Furthermore, in order to make possible an economical manufacture and easy installation of the swiveling piston, it is further provided that the swiveling piston is formed by a section of a rod with flat rectangular cross section and is constructed at three front edges with a receiving groove for a seal.

The transfer of the magnified piston force onto the setting part is done in such a manner that the first lever arm of the swiveling piston pivotably engages a transverse slot in the FIG. 1 is a schematically illustrated vertical cross section of a worktool of the above-described type, and

FIG. "2 is a schematically illustrated front view of the tool according to FIG. 1.

A tool according to the drawings has a tubular bearing housing 1 for a setting unit 3 which is translatably movable ramlike in an axial direction by a hydraulic or pneumatic drive 2, and which setting unit is, for example, suitable for setting blind rivets in connection with a sethead or for punching of sheet metal in connection with a stamping head 5. The bearing housing 1 and the sethead 3 each 'haveon both ends a receiving thread la or 30 for the sethead 4 or the stamping head 5 or other drawing and/or pressure devices.

The drive 2 of the tool of the invention has a two-arm lever 2a which pivotably engages a transverse slot 3b of the setting unit 3 with a short first lever arm 24a. The'two-arm lever 2a furthermore has a second lever arm Zab which is substantially longer thanthe first lever arm 2aa and is supported pivotably pressure-tight between the lever arms by means of an axial bolt 2b in a wall opening'of a cylinder chamber 2c. The'first lever arm 2aa of the two-arm lever 2a projects through the wall opening of thecylinder chamber 20 to the outside thereof and engages the setting unit 3 in the manner which has already been described.

At least the second lever arm Zab of the two-arm lever 2a is formedby a section of a bar with a flat rectangular cross sec tion and is provided at three from edges with a receiving groove'2ac for a cord seal 2d. The second lever arm 2ab of the two-arm lever 2a forms togetherwith the cylinder'chamber 2a a rotary or swiveling piston cylinder unit which can be operated either in adouble-acting manner or against the force the cylinder chamber 2c forms an'easily grippable handle for the bearing housing 1. I

As can be taken particularly from FIG. 2, the walls of the cylinder chamber 20 which extend parallel to the directionof piston movement are formed by cover plates 23,23 which are removably secured to their circular sector-shaped walls.

The apparatus which has been described as a'n-example has the particular advantage that, by using only one drive, holes can be punched and blind rivets can be placed into said holes.

The pressure acting on the setting unit can be increased by widening the lever arm Zab over its entire length or in the zone of its free end. Thus, the pressure surface is enlarged.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In a pressure-operated tool having housing means, means defining a first opening in said housing means extending axially thereof, means defining a second opening in said housing means extending transverse to the axis of said first opening and a setting unit axially slidably mounted in said opening,

said setting unit having first connecting means thereon movable therewith, the improvement comprising:

pressurizable chamber means connected to said housing means; lever means and pivot means for pivotably securing said lever means on said chamber means, said lever means having a first arm extending outwardly of said chamber means from one side of said pivot means and into said second opening of said housing means, said first arm having second connecting means thereon coupled to said first connecting means, said lever means having a second arm, longer than said first arm, in said chamber means on the other side from said pivot means and defining a pivotable piston; and coupling means on said chamber means on one side of said pivotable piston for permitting an attachment of a source of pressurized fluid thereto, said pivotable piston being pivot-able in response to a pressurization of said chamber means by said pressurized fluid to thereby effect a movement of said setting unit axially of said housing means.

2. A pressure-operated tool according to claim 1, including resilient means for urging said pivotable piston to one end of said chamber means.

3. A pressure-operated tool according to claim 1, wherein said chamber means defines a handle for said pressureoperated tool.

4. A pressure-operated tool according to claim 1, wherein said pivotable piston is composed of an elongated flat bar extending outwardly from said pivot means and having a rectangular cross section, said bar having means defining grooves along three edges thereof adjacent the walls of said chamber means and adapted to receive a seal slidably engageable with said walls of said chamber means.

5. A pressure-operated tool according to claim 4, wherein said walls of said chamber means comprise an arcuate wall extending on a radius of said pivot means and a pair of side walls extending parallel to opposite edges of said pivotable piston and connected to said arcuate wall, said seal on said pivotable piston slidably engaging said pair of side walls and said arcuate wall, said walls of said chamber means further defining an easily grippable handle.

6. A pressure-operated tool according to claim 1, wherein said setting unit includes means defining first and second threaded connections on opposite ends thereof, said first threaded connection on one end being adapted to engage a sethead and said second threaded connection on the opposite end being adapted to engage a stamping head.

7. A pressure-operated tool according to claim 6, wherein said housing means includes means defining third and fourth threaded connections on opposite ends thereof, said third threaded connection on said one end being adapted to engage said sethead and said fourth threaded connection on said other end being adapted to engage said stamping head.

8. A pressure-operated tool according to claim 1, wherein said pivot means includes means defining a seal between said chamber means and said housing means.

9. A pressure-operated tool according to claim 1, wherein said chamber means comprises an arcuate wall extending on a radius of said pivot means, a pair of opposed side walls extending parallel to the direction of movement of said pivotable piston and being connected to said arcuate wall and a pair of inclined and opposed end walls, said arcuate wall, said side walls and said end walls defining an arcuate sector of a circle and an easily grippable handle, said pivot means being located at the center of said sector of said circle. 

1. In a pressure-operated tool having housing means, means defining a first opening in said housing means extending axially thereof, means defining a second opening in said housing means extending transverse to the axis of said first opening and a setting unit axially slidably mounted in said opening, said setting unit having first connecting means thereon movable therewith, the improvement comprising: pressurizable chamber means connected to said housing means; lever means and pivot means for pivotably securing said lever means on said chamber means, said lever means having a first arm extending outwardly of said chamber means from one side of said pivot means and into said second opening of said housing means, said first arm having second connecting means thereon coupled to said first connecting means, said lever means having a second arm, longer than said first arm, in said chamber means on the other side from said pivot means and defining a pivotable piston; and coupling means on said chamber means on one side of said pivotable piston for permitting an attachment of a source of pressurized fluid thereto, said pivotable piston being pivotable in response to a pressurization of said chamber means by said pressurized fluid to thereby effect a movement of said setting unit axially of said housing means.
 2. A pressure-operated tool according to claim 1, including resilient means for urging said pivotable piston to one end of said chamber means.
 3. A pressure-operated tool according to claim 1, wherein said chamber means defines a handle for said pressure-operated tool.
 4. A pressure-operated tool according to claim 1, wherein said pivotable piston is composed of an elongated flat bar extending outwardly from said pivot means and having a rectangular cross section, said bar having means defining grooves along three edges thereof adjacent the walls of said chamber means and adapted to receive a seal slidably engageable with said walls of said chamber means.
 5. A pressure-operated tool according to claim 4, wherein said walls of said chamber means comprise an arcuate wall extending on a radius of said pivot means and a pair of side walls extending parallel to opposite edges of said pivotable piston and connected to said arcuate wall, said seal on said pivotable piston slidably engaging said pair of side walls and said arcuate wall, said walls of said chamber means further defining an easily grippable handle.
 6. A pressure-operated tool according to claim 1, wherein said setting unit includes means defining first and second threaded connections on opposite ends thereof, said first threaded connection on one end being adapted to engage a sethead and said second threaded connection on the opposite end being adapted to engage a stamping head.
 7. A pressure-operated tool according to claim 6, wherein said housing means includes means defining third and fourth threaded connections on opposite ends thereof, said third threaded connection on said one end being adapted to engage said sethead and said fourth threaded connection on said other end being adapted to engage said stamping head.
 8. A pressure-operated tool according to claim 1, wherein said pivot means includes means defining a seal between said chamber means and said housing means.
 9. A pressure-operated tool according to claim 1, wherein said chamber means comprises an arcuate wall extending on a radius of said pivot means, a pair of opposed side walls extending parallel to the direction of movement of said pivotable piston and being connected to said arcuate wall and a pair of inclined and opposed end walls, said arcuate wall, said side walls and said end walls defining an arcuate sector of a circle and an easily grippable handle, said pivot means being located at the center of said sector of said circle. 